Method of making a personalized bone graft

Abstract

An anatomically-shaped, human bone graft may be cultivated ex vivo using a bioreactor capable of perfusing large complex porous scaffolds. Scaffolds derived from image-based modeling of a target are seeded with human mesenchymal stem cells and cultivated. A bioreactor configured to house complex three-dimensional scaffold geometries provides controlled flow for perfusion of the cells. Dense uniform cellular growth can be attained throughout the entire scaffold as a result of the medium perfusion. In an embodiment, the bioreactor has a mold into which perfusion medium is pumped under pressure and multiple ports through which the medium exits the mold.

1 - 3 . (canceled) 
     
     
         4 . A tissue engineering system comprising:
 a porous scaffold disposed within a three-dimensional vessel with an internal surface;   a bioreactor having a combination of inlet ports and outlet ports totaling at least three ports wherein the ports are placed to permit flow communication between at least one lumen and an internal volume defined by the internal surface of the vessel; and   a flow mechanism configured to:
 introduce a perfusate into the bioreactor via one of at least one inlet port, and 
 circulate the perfusate between the at least one lumen and the internal volume of the vessel, 
   wherein placement of the combination of inlet ports and outlet ports are determined based on a shape of the porous scaffold and establish a pattern that distributes perfusate throughout the porous scaffold.   
     
     
         5 . The system of  claim 4 , wherein the porous scaffold matches a target anatomy of a patient. 
     
     
         6 . The system of  claim 5 , wherein the internal surface of the vessel is configured to correspond to the target anatomy of the patient. 
     
     
         7 . The system of  claim 4 , wherein the porous scaffold comprises decellularized bone. 
     
     
         8 . The system of  claim 4 , wherein the internal surface of the three-dimensional vessel conforms to the shape of the porous scaffold. 
     
     
         9 . The system of  claim 4 , wherein the bioreactor forms a recess therein, and wherein introducing the perfusate into the bioreactor comprises introducing the perfusate into the recess of the bioreactor. 
     
     
         10 . The system of  claim 9 , wherein the three-dimensional vessel is disposed within the recess. 
     
     
         11 . The system of  claim 4 , wherein the flow mechanism is further configured to provide at least two different fluid inlet flow rates or at least two different fluid outlet flow rates. 
     
     
         12 . The system of  claim 4  wherein the placement of the combination of inlet ports and outlet ports are further determined by computer aided modeling. 
     
     
         13 . The system of  claim 4 , wherein the flow mechanism includes a pump. 
     
     
         14 . The system of  claim 4 , wherein the at least one inlet port comprises a first inlet port and a second inlet port, and wherein the first inlet port and the second inlet port provide different fluid flow rates. 
     
     
         15 . The system of  claim 4 , wherein combination of inlet ports and outlet ports comprises a first outlet port and a second outlet port, wherein the first outlet port and the second outlet port provide different fluid flow rates. 
     
     
         16 . The system of  claim 4 , wherein the flow mechanism is configured to cycle between different flow rates. 
     
     
         17 . The system of  claim 4 , wherein the flow mechanism is configured to apply a pressure differential to force the perfusate to perfuse the porous scaffold. 
     
     
         18 . The system of  claim 4 , wherein the flow mechanism provides a flow pattern associated with the shape of the porous scaffold. 
     
     
         19 . The system of  claim 4 , wherein the combination of inlet ports and outlet ports is configured to introduce perfusate directly into the porous scaffold at multiple points about the porous scaffold such that an architecture of forming bone correlates to interstitial flow characteristics. 
     
     
         20 . The system of  claim 4 , configured to produce a flow rate of at least 0.4 ml/minute. 
     
     
         21 . The system of  claim 4 , wherein the combination of inlet ports and outlet ports is configured in a pattern that distributes perfusate through multiple surface portions of the porous scaffold and out through at least one second surface of the porous scaffold, and further wherein at least one second surface portion is determined responsively to a three-dimensional flow model of the porous scaffold. 
     
     
         22 . The system of  claim 4 , wherein the perfusate includes cells derived from a patient. 
     
     
         23 . The system of  claim 4 , wherein the porous scaffold is seeded with stem cells derived from a patient.